Arduino Reset Peristaltic Pumps / Relays? [RESOLVED]

Sorry for making a video question, but seemed quicker and visuals are always nice right? |500x281 (click to play video question)

Textual version: I've got a transformer taking AC power and converting down to 12v 3AMPs (even tried a 1A) that I'm feeding power to 10 channels of a 16 channel relay (daisy chained). I then am running power from each relay (normally closed side) out to ten 12v peristaltic pumps. From transformer I'm running a second set of power (VC/GRN) to the needed main 12v power on the relay board. From the main power source of the relay board, I'm running a ground line that is daisy chained to each peristaltic pump. Lastly I've got a second set of power (VC/GRN) running from main power of relay to a breadborad that powers LEDs, RTC, SD Card Reader and Arduino. I have grounded one of the 5v pins on the relay to the breadboard.

Issue is that I when I run any pump higher than first pump (aka relay #1) my Arduno resets when killing power to pump. I've seen other's get around this issue on here using something called a snub, but I'm not sure what parts I need to make that or where I should hook it in for each channel.. any information would be greatly appreciated.

Thanks!

Sorry video was set to private ugh, updated. Anyone have any insight?

Try a 1N4007 across motor terminals. Cathode to the most positive terminal, anode to the most negative, terminal.

Example outputs: |500x367

Daisy chaining power is never recommended BTW.

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Show us a good schematic of your circuit.

The Arduino should get power form a source other than the external 12V supply.

Typical way you should wire a relay board. |500x275

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Thank you LarryD! I've placed an order for these and should be here any day. My only question is when you say:

Try a 1N4007 across motor terminals. Cathode to the most positive terminal, anode to the most negative, terminal.

Are you saying to actually connect the positive and negative terminals on the motors together.. using a single 1N4007 per motor, or are you saying use a 1N4007 per terminal (1 for live wire, 1 for ground)? Just never heard of connecting terminals together before, so wanna make sure I understand completely.

Here is my crude schematic of what I have: |500x351

Thanks again!

|500x351

  • feed motor ground(s) from source, not relay board
  • stop daisy chaining motor grounds (is that part of the solution, or just recommend to never to do).
  • feed breadboard from source, not relay board.
  • use 0.1pF (are these ok?) and 47pF (are these ok?) capacitor on 12v side of breadboard.
  • feed power to Arduino from breadboard still.

Last two questions: Motor terminals; looks like you have triangles connecting positive and negative. Is that indeed where the 1N4007(s) go (per motor - arrow indicating mount direction)?

If I go back to using my 12v - 1A transformer (that seemed to be working, other than have this same issue), does the above capacitor specs still apply?

I can't thank you two enough, this has truly been helpful!

The triangles are actually the diode symbols ... anode to GND, cathode to +12V. The 1A power supply would be not be enough power ... especially if multiple relays and pumps are enabled. The suggested capacitors shown are in microfarads ... not really part of the solution but will help filter breadboard power rails.

Hi,
As said above use a star pattern to connect your motor grounds.
Connect the Arduino gnd directly to the gnd of the power supply.

Tom… :slight_smile:

So far everything is working great now! I was able to still keep the 1A power source (cause my application indeed only uses 1 motor at a time).

The only problem I have now is when ever it is running I keep hearing "We are the Champions" song playing in my head, just something I will have to get over I guess.

Thanks again!!

"We are the Champions" Is that a String or char array?

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devinrayolsen: So far everything is working great now! I was able to still keep the 1A power source (cause my application indeed only uses 1 motor at a time).

The only problem I have now is when ever it is running I keep hearing "We are the Champions" song playing in my head, just something I will have to get over I guess.

Thanks again!!

What did you do to fix the problem? To make this thread useful to others please tell us what the problem was? Tom..... :)

I did the following steps to fix my issue:

  • Feed GND to pump motors from power source, not relay board
  • Stop daisy chaining pump motor GNDs; instead (like power) each GND gets its own line now.
  • Feed breadboard VCC/GND from power source, not relay board.
  • Connected 1N4007 diodes across positive and negative terminals of pump motors.
  • Use 0.1pF and 47pF capacitor on 12v side of breadboard.

The issue was two fold. 1) the way I was connecting the grounds to the motors, and 2) needed 1N4007 diodes across each pump's motor terminals. Capacitors were not part of the solution, but indeed lower the noise issue I was having on my breadboard and pH/EC water sensors for my project. A+